If you're working with an agent, he/she should be providing all these resources for you. If you're not working with an agent you should be!
There's nothing wrong with doing your own contractor's inspection even though the sellers have provided one. The benefit is a second opinion on the property as well as you get to walk through the property with the contractor who will explain/highlight details of the property that need to be addressed.
I highly recommend Skip Walker.
He works all over the Bay Area. His reports are 70-85 pages vs some reports that I've seen which are 10-20 pages. Skip is very thorough!
Based on the results of his inspection, you can then decide if you need to bring in specialists.
Maybe consider hiring a general contractor to inspect and prepare written estimates for you if any of these areas needed to be updated to code. If you will need to put more money in the property because of the updates, you might be able to negotiate down your purchase price.
I recommend Eversound Development & Construction
I worked with Ken on a number of projects. He and his contractors has given me a lot of good education and advice.
I recommend Jay DeWolf - DeWolf Inspections.
I have known Jay for probably 15 years now.
I use him for my own purchases as well as for my client purchases.